1. Field of the Invention
One or more embodiments of the present invention relate to an organic light emitting device.
2. Description of the Related Art
Organic light emitting devices (OLEDs), which are self-emitting devices, have wide viewing angles, high contrast, and quick response time, and thus have drawn a large amount of public attention. Furthermore, OLEDs have a low operating voltage and can realize multi colored images. Thus, a lot of research into organic emitting devices has been carried out.
When current is supplied to an anode and a cathode respectively formed on both sides of an emitting layer, electrons and holes recombine in the emissive layer and thus light is emitted. In general, an OLED may include an organic layer having a multi-layered structure including hole injection layer (HIL), hole transport layer (HTL), an electron transport layer (ETL), and/or electron injection layer (EIL) formed on either end of the emitting layer in order to obtain excellent light emitting properties.
A single color OLED has an anode/emitting layer/cathode structure. The OLED may emit a variety of colors according to the types of materials forming the emitting layer. A method of stacking materials emitting red, green, and blue light, which are the three primary light colors, may be used to prepare a white light emitting OLED.
However, the blue light emitting efficiency of such a white light emitting OLED is too low.
The blue light emission is closely related to the color coordinate, color reproduction ratios, and lifetime (or lifespan) of the OLED.
However, the color coordinate, color reproduction ratios, and lifetime of existing OLEDs are not satisfactory, and thus there is a need to improve these properties.